Along with the widely spread use of a portable radio terminal such as a portable telephone, a note book PC or the like in recent years, studies have been progressed on a plate shaped battery for use in the portable radio terminal.
FIG. 30 is a perspective view of a prior art plate shaped battery. Referring to FIG. 30, when a plate shaped battery 300 is mounted in a portable radio terminal, the plate shaped battery 300 is placed on a support plate 320. The plate shaped battery 300 is constructed of: a battery core 311; an anode terminal 312; and a cathode terminal 313. A laminated film 302 wraps the battery core 311. The battery core 311 is electrically connected to the anode terminal 312 and the cathode terminal 313.
The battery core 311 is formed by winding a prescribed laminate in turns laying one on top of the preceding one. The laminate includes a thin plate connected to the anode terminal 312, a thin plate connected to the cathode terminal 313 and a separator interposing therebetween, wherein a space between the thin plates is filled with an electrolyte.
The laminated film 302 is provided so as to cover a part of the anode terminal 312 and a part of the cathode terminal 313. By contact bonding parts of the laminated film 302 therebetween, formed are an electrode seal portion 302f, and seal portions 302d and 302e. The laminated film 302 has a three-layer structure composed of a resin layer, an aluminum foil and a resin layer in this order.
In the electrode seal portion 302f, the anode terminal 312 and the cathode terminal 313 are sealed being sandwiched by parts of the laminated film 302. The electrode seal portion 302f is formed so as to extend in one direction. The seal portion 302d is formed so as to extend in a direction almost perpendicular to the one direction of the electrode seal portion 302f. The seal portion 302d is formed so as to extend along the battery core 311. The seal portion 302d is in contact with the support plate 320. The seal portion 302e is formed so as to extend almost in parallel to the one direction along which the electrode seal portion 302f. With the electrode seal portion 302f, and the seal portions 302d and 302e, the electrolyte inside of the battery core 311 can be prevented from leaking outside thereof.
Parts of the anode terminal 312 and the cathode terminal 313, not covered by the laminated film 302 are electrically connected to a circuit board of a portable telephone, a note book PC or the like.
FIG. 31 is a sectional view taken on line XXXI—XXXI of FIG. 30. Referring to FIG. 31, the plate shaped battery 300 is placed on the support plate 320. The support plate 320 and the plate shaped battery 300 are in contact with each other at the seal portion 302d. Since the seal portion 302d is not shown in the sectional view shown in FIG. 31, the plate shaped battery 300 are depicted as if it floated in the air above the support plate 320 with a gap therebetween. The laminated film 302 is constructed of: resin layers 302a and 302c, and an aluminum foil 302b. The anode terminal 312 protrudes from the electrode seal portion 302f. To the anode electrode 312, a contact pin is put into contact in order to supply power to a portable telephone from the plate shaped battery 300. Thereby, a force is imposed on the anode terminal 312 from a direction shown by an arrow 330.
FIG. 32 is a sectional view taken on line XXXII—XXXII of FIG. 30. Referring to FIG. 32, the plate shaped battery 300 is placed on the support plate 320. The laminated film 302 wraps the battery core 311. The seal portion 302d of the plate shaped battery 300 is in direct contact with the support plate 320. Since in the seal portion 302d, the laminated film 302 has a two layer structure of one on the other, a combined thickness thereof is thicker than that of the laminated film 302 in the other parts. As a result, only the seal portion 302d is in contact with the support plate 320 and the other parts are not in direct contact with the support plate 320. A height H1 of a top surface of the plate shaped battery 311 above the support plate 320 is H1=0.5 to 0.6 mm.
In recent years, the plate shaped battery for use in portable telephone has been developed toward a smaller size and a lighter weight owing to downsizing and saving more of weight on the side of the portable telephone. Hence, as a substance of the anode terminal 312 and the cathode terminal 313, a light aluminum alloy has been adopted and moreover, a thickness thereof has been reduced. Consequently, as shown in FIG. 31, when a force is exerted on the anode terminal 312 from the direction shown by the arrow 330, the anode terminal 312 is bent. Once the anode terminal 312 is bent, the anode terminal 312 comes to has difficulty in connecting to other terminals such as a contact pin, which has led to a problem since loose contact arises therebetween.
Furthermore, as shown in FIG. 32, since the laminated film 302 and the support plate 320 are only in contact with each other at the seal portion 302d, another problem has arisen since not only does positioning of the laminated film 302 become unstable, but a size (or a thickness) of the plate shaped battery 300 grows larger.
In light of the problems, the present invention has been made in order to solve them. It is accordingly, an object of the present invention is to provide a plate shaped battery and a portable radio terminal capable of surly positioning an electrode terminal in place, by or in which no loose contact of the electrode terminal arises.
It is another object of the present invention is to provide a plate shaped battery and a portable radio terminal capable of not only surly positioning a wrapping member in place but also downsizing themselves.